Richard Sherman says on Twitter that he won his appeal with the NFL. / Tom Szczerbowski, Getty Images

by Lindsay H. Jones, USA TODAY Sports

by Lindsay H. Jones, USA TODAY Sports

Seattle Seahawks cornerback Richard Sherman was cheered by his teammates Thursday, but it had nothing to do with his play on the field.

Sherman scored a rare victory against the NFL in winning his appeal of a four-game suspension for violating the league's performance-enhancing drug policy. He argued that there were errors in the chain of custody of his urine specimen.

"A lot of people told me my chances were slim to none," said Sherman, who broke the news on his Twitter account in the morning.

Quarterback Russell Wilson said players in the locker room cheered when they learned of the ruling. If Sherman had lost, the cornerback would have missed the playoffs and put the Seahawks at a severe disadvantage.

Now he will play Sunday with Seattle needing a win and a San Francisco 49ers loss to elevate from the No. 5 seed to the NFC West champs.

"We just had to prove the case," Sherman's agent, Kevin Poston, told USA TODAY Sports. "They made mistakes with his sample, and the truth came out."

Sherman traveled to St. Louis last week to make his appeal before arbitrator and former St. Louis Rams executive Bob Wallace.

He stated when he provided a urine sample on Sept. 17, the specimen cup had a leak, prompting the collector to use a second cup. Sherman's lawyers claimed this was a breach in protocol.

A year ago, Milwauke Brewers slugger and NL MVP Ryan Braun violated Major League Baseball's drug policy before winning his appeal on a similar technicality.

"The decision really relied most heavily on the collection problem, and it comes down to that the arbitrator believed Richard Sherman over the collector's recounting of the facts," said one of Sherman's attorneys, Maurice Suh. "This is a case in which there were two different versions â?? the collector tried to refute what Richard had said about what had happened, and frankly, we didn't feel the collector was believable and we tried to bring that up in cross examination."

On Sunday, Sherman sounded as if he expected to lose and perhaps sue the NFL.

"The league's argument was they are allowed to make mistakes, and they're allowed to break the rules, and they can get away with it," Sherman said. "It's up to them. The appeal officer is paid by the league, so if he goes their way, that's what it is. It's not an even playing field in the appeal room."

But Thursday, Sherman was thankful for the ruling, tweeting on his verified account: "Thank you to the NFL for upholding the truth!"

Said NFL spokesman Greg Aiello: "We are reviewing the decision, but decline comment at this time due to the confidentiality provision of the program."

Said Poston: "Richard Sherman, he didn't go to Stanford for nothing. He's smart. I'm proud of the way he stood up for himself on this."

Sherman has quickly become one of the Seahawks best players and a crucial member of the defense â?? with seven interceptions (tied for second-most in the league) and three forced fumbles. In last week's win against San Francisco, Sherman scored on a 90-yard touchdown after recovering a blocked field goal, and later intercepted a pass in the end zone.

Fellow starting cornerback Brandon Browner also received a four-game suspension for a positive drug test, but unlike Sherman, he did not appeal. Browner will serve the final game of his suspension Sunday, and will be allowed to rejoin his teammates for the start of the playoffs.